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Finding the Fourth Proportional to 668.79, 921.44 and 491.40

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Solution

The fourth proportional to 668.79, 921.44 and 491.40 is: 677.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.79 : 921.44 = 491.40 : x
  2. Step 2: Convert to fraction form
    668.79/921.44 = 491.40/x
  3. Step 3: Cross multiply
    668.79x = 921.44 × 491.40
  4. Step 4: Simplify right side
    668.79x = 452,795.62
  5. Step 5: Solve for x
    x = 452,795.62/668.79
  6. Step 6: Final answer
    x = 677.04

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.